Fiber blowing apparatus



July 17, 1962 F. o. HESS 3,044,110

FIBER BLOWING APPARATUS Filed Deg. 23, 1957 INVENTOR. FREDERIC O. HESS ATTORNEY.

3,044,110 FIBER BLOWING APPARATUS Frederic 0. Hess, Philadelphia, Pa, assignor to Selas Corporation of America, Dresher, Pa., a corporation of Pennsylvania Filed Dec. 23, 1957, Ser. No. 704,793 4 Claims. (Cl. 182.5)

This invention relates to improved apparatus for producing fibers from a thermoplastic mineral material such as glass, rock or slag, and is particularly directed to blowing the fibers and keeping them plastic while the blowing takes place.

-One of the methods presently used for manufacturing fibers is to deposit molten fiber forming material in a rotating basket or spinner having a plurality of radially directed orifices. As the spinner is rotated the material is thrown out by centrifugal force, and, as it is freezing, is attenuated into fibers. Various means have been employed to increase the attenuation and therefore decrease the diameter of the fibers. Each of these means, however, has some disadvantage that prevents it from being used to any great extent commercially.

It is an object of the invention to provide apparatus for controlling the attenuation of fibers discharged from a rotating basket. It is a further object of the invention to provide apparatus for heating a rotating fiber producing apparatus, and the environment adjacent thereto so that the temperature of the discharged fiber forming material is accurately maintained at a desired value.

An additional object of the invention is to provide apparatus for forming fine fibers of a thermoplastic material, and protecting the fibers as they are being formed.

The apparatus of the invention includes a rotating element into which molten fiber forming material is deposited and from which it is discharged radially in a multiplicity of small streams. Located above this element is an annular burner that serves to maintain the temperature of the fibers by radiant heat as they are discharged. Immediately beyond the rotating element in a radial direction is an annular slot through which an attenuating material such as steam or hot air is discharged at an angle to the path of travel of the fibers. material serves further to attenuate the fibers to a very small and uniform diameter.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a view, in section, of one form of the apparatus,

FIGS. 2 and 3 show modified forms of the burner that is used with the apparatus of FIG. 1, and

FIG. 4 shows a different burner arrangement.

Referring to FIG. 1 of the drawings, there is shown an elongated structure forming an internal burner 5 that is supported in a fixed position by a suitable means 6, only a portion of which is shown. The burner is cylindrical in shape and forms a central passage 7 that is surrounded by a first annular chamber 8 and a second annular chamber 9. Chamber 8 is supplied with a fuel mixture through a pipe 11. The mixture is discharged through a plurality of rings or ports 13 forming a burner screen in the lower end 12 of the chamber. As the fuel is discharged it burns for a purpose to be described below. Cooling water is circulated through chamber 9.

This

3,044,110 Patented July 17,1962

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Surrounding burner 5 is a cylindrical quill 14 that is mounted for rotation on a stationary support 15 which may well be a portion of supporting means 6. The upper end of quill 14 has a pulley 16 attached to it, with the pulley and quill 14 being mounted on support 15 by bearings 17 and 18. 'The lower end of quill 14 is formed as a closed basket 19 that is provided in its periphery with a multiplicity of radially directed openings 21. Annular member 22, known as a spinner, is mounted on quill 14 and rotates therewith. The outer wall 23 of the spinner is substantially parallel to and radially displaced from the wall of basket 19, and is provided with a multiplicity of radially directed openings 24 that may be generally aligned with openings 21.

Located above and around the spinner is a fiber heating and blowing assembly 25 which acts as a shield to protect the fibers thrown from the spinner from drafts or air currents that may distort them before they are attenuated. This assembly includes a radially l extending annular burner frame 26, that is suitably attached to support 15, and has therein an annular ceramic refractory part 27 formed on its lower face with a concave surface 28 that is substantially semi-circular in section. An annular fuel manifold 29 surrounds the refractory; Extending between manifold 29 and the outer edge of surface 28 is an annular fuel slot 31 that is so formed that fuel is discharged parallel to the surface. Below manifold 29 is a second annular manifold 32 for a fiber blowing medium that is provided with an annular discharge slot 33 directed downwardly at an acute angle to the axis of the spinner. An axially extending annular sleeve 34 surrounds the spinner with an annular space between the two.

In operating the apparatus, fuel discharged through ports 13 is ignited to heat the interior of basket 19, with the products of combustion being discharged upwardly through the central passage 7 and between quill 14 and the exterior of chamber 8. Fuel being disbharged through slot 31 is also ignited to burn as it flows across surface 28. This burning heats surface 28Ito incandesence so that radiant heat of high intensity is directed downwardly in the space between wall 23 of the spinner and sleeve 34.

The inner edge of surface 28 is so curved that the products of combustion from this burner are directed downwardly against the top of spinner 22 to help maintain-this part at a high temperature about equal to that of the molten fiber forming material being used. The products of combustion are disposed by striking the spinner so that they can have no efiect on the material being thrown therefrom.

Basket 19 and spinner 22 are rotated by some suitable means, such as a motor driving pulley 1 6 through a belt, at a speed of approximately 3000 r.p.m. When the apparatus is started burner 5 is ignited to heat the basket and spinner to the temperature of the fiber forming material,

after which burner 5 is turned off. Thereafter the basket is kept hot by the material. A stream of fiber forming material, such as molten glass, for example, is dischargedfrom an opening in the bottom of a supply tank 35 in a continuous stream through passage 7 into basket 19. From there it is thrown by centrifugal force through openings 21 in a smooth layer against the inner surface of wall 28 of the spinner. This wall is maintained, by adjusting the supply of fuel to burner 25, at a temperature of between 1800" F. and 1950 F., or as near the glass tem. perature as possible, so that the glass will be thrown through openings 24 evenly all around the spinner. As the glass is thrown in uniform tiny streams from openings 24 it is kept at temperature by the radiant heat from surface 28 until it is struck by a fiber blowing fluid medium such, for example, as steam being discharged at high velocity through slot 3B. The small streams of glass are directed downwardly, attenuated and reduced in diameter to produce a good grade of fiber. The fibers can be collected in any conventional manner.

The form of the invention shown in FIG. 2 differs from that previously described in the manner in which the radiant burner used to heat the spinner is constructed. In this case a manifold 41 for fuel is placed around the quill 14, and below it there is providedan annular refractory block 42 that has a concave surface 43-. Fuel is discharged from manifold 41 through an annular slot 44 across surface 43. The fuel burns along that surface to heat it to incandescence so that radiant heat will be radiated downwardly in the space between wall 23 of the spinner and sleeve 34. Because of the shape of surface 43, the products of combustion are directed more closely along wall 23 to maintain this wall at temperature.

In FIG. '2 sleeve '34 is shown as having a chamber 45 formed around its outer surface through which cooling water can be circulated to prevent this sleeve from overheating.

In FIG. 3 the ceramic surface of the radiant burner is shown as having still a different shape. In th's case an annular fuel manifold 46 is placed around quill 14. Below the manifold is a ceramic ring 47 that has a concave surface 48 facing generally toward the top surface of spinner 22. Fuel is discharged across the surface from manifold 46 through an annular slot 49. In this form of the invention, as, in the previously described forms, surface 48 is heated to incandescence as the fuel burns across it. The radiant heat produced thereby is directed against the top of the spinner as well as toward the space between the spinner and sleeve 34.

The embodiment of the invention shown in FIG. 4 differs from those previously described in that the front of the burner is shielded from the fibers discharged from spinner 22, and the products of combustion are withdrawn through the spinner. Referring to the figure, it be seen that the frame is so shaped that the annular refractory channel 51 of the burner is shorter on its inner edge than on its outer edge, so that the depression is directed toward the outer edge and top of the spinner 22. A deflector plate 52 of material transparent to heat rays, such as a high silica glass, is placed across the front of the depression. This deflector plate is held in position by a suitable slot in frame 26 below the fuel supply slot 31. It will be seen that plate '52 does not extend entirely across the front of the burner, but provides an annular slot '53 through which the products of combustion escape.

Spinner 22 is provided in its upper surface with a plurality of air scoops 54 adjacent to openings through said surface. These scoops are at an angle to the surface so that as the spinner rotates products of combustion escaping from the burner through slot 53 are'drawn into the spinner and discharged through the bottom thereof.

It will be seen that with this form of the invention radiant heat from the burner is directed not only in the space between spinner 22 and slot 33, but also against the top of the spinner. Thus, the spinner as well as the space into which the glass is thrown is kept at the desired temperature. In addition, the hot products of combustion from the burner are passed through the spinner tov add additional heat to the glass. 7

In each form of the invention the burner frame and its support surround the spinner both above and on the outside thereof to form an effective shield. This arrangement prevents any stray air currents from being induced in the region adjacent to that where the fiber blowing takes place. The arrangement is such that the glass or other material is protected and maintained at temperature until the moment blowing takes place. This arrangement promotes the production of finer and more uniform fibers than it has previously been possible to make.

In each of the embodiments described the fuel forthe radiant burner is disclosed as being discharged across the ceramic surface as an annular sheet. In some cases, however, it may be desirable to provide means to break the sheet into a plurality of individual jets discharged radially across the surface. The action and operation of the burner is the same in either case.

From the above description it will be seen that I have devised apparatus that will keep fiber forming material in a molten condition and at the optimum temperature until the moment that it is struck by the attenuating blast which forms the fibers. By keeping the entire spinner throwing Wall at an even temperature, which can readily be adjusted for the material used, finer and more uniform fibers can be produced than was previously possible.

While in accordance with the provisions of the Statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparcut to those skilled in the art that changes may be made in the from of the apparatus disclosed without departing from the spirit and scope of the invention set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In apparatus for forming fibers, a hollow circular element having a wall provided with a multiplicity of radially extending openings, means to rotate said element around a vertical axis to discharge material through said openings, a shield extending above and around said element to leave anannular space between the two thereby to protect said space from air currents, burner means on said shield, said burner means including an annular refractory plate having a surface facing said annular space and a portion of said element adjacent to said wall, means to direct a fuel gas mixture across said surface to burn thereon to heat said surface to incandescence thereby to direct radiant heat against said' element and material discharged from said openings, means in said shield radially outward of said surface to direct a fluid under pressure across material being discharged from said openings and means forming air scoops on said element operative, upon rotation thereof, to draw products of combustion from said surface into said element.

2. The combination of claim 1 including an annular deflector extending between the surface of said burner and said space, said deflector serving to direct the products of combustion toward said air scoops.

3. In apparatus for forming fibers, an annular shield having a radial portion and an axial portion, a burner attached to said radial portion and comprising a ring of ceramic material having a concave face directed substantially axially of said space, means to supply a fuel mixture radially inward across said face to burn across said face to heat the same to incandescence whereby radiant heat will be projected axially through said shield, a hollow rotating element positioned concentrically in and surrounded above and radially outward by said shield and through which molten material is discharged in a multiplicity of streams into said space below said ceramic material, means in said axial portion located radially outward of said ceramic material through which a fluid under pressure is blown across said streams of material and means on said rotating element operative to draw products of combustion into said element as it is being discharged from said face.

4. Fiber forming apparatus comprising in combination a rotating element from which'fiber forming material is discharged radially in a multiplicity of streams, means forming a shield having a radial portion and an axial portion above and around said element so located and dimensioned that an annular space is formed around said element with the shield protecting said element from air currents above and radially beyond the same, means in said radial portion to produce radiant heat directed into said space said means including an annular block of ceramic material having a concave surface facing said rotating element and means to supply a fuel mixture across said surface to burn along the same, means forming an annular discharge slot in said axial portion radially outward of said radiant heat producing means with said slot directed at an acute angle to the axis of said annular portion in a direction away from said radial portion, means to discharge a fluid under pressure through said slot and beneath the heat produced by said radiant heat producing means, an annular deflector extending substantially across said surface from the outer edge thereof, the products of combustion being discharged between the inner edge of said deflector and said surface, and means on said rotary element to draw the products of combustion into the same.

References Cited in the file of this patent UNITED STATES PATENTS 2,199,309 Freudenberg Apr. 30, 1940 

